1 /* SPDX-License-Identifier: GPL-2.0-only */
2 /*
3 * VFIO API definition
4 *
5 * Copyright (C) 2012 Red Hat, Inc. All rights reserved.
6 * Author: Alex Williamson <alex.williamson@redhat.com>
7 */
8 #ifndef VFIO_H
9 #define VFIO_H
10
11
12 #include <linux/iommu.h>
13 #include <linux/mm.h>
14 #include <linux/workqueue.h>
15 #include <linux/poll.h>
16 #include <uapi/linux/vfio.h>
17 #include <linux/iova_bitmap.h>
18
19 struct kvm;
20 struct iommufd_ctx;
21 struct iommufd_device;
22 struct iommufd_access;
23
24 /*
25 * VFIO devices can be placed in a set, this allows all devices to share this
26 * structure and the VFIO core will provide a lock that is held around
27 * open_device()/close_device() for all devices in the set.
28 */
29 struct vfio_device_set {
30 void *set_id;
31 struct mutex lock;
32 struct list_head device_list;
33 unsigned int device_count;
34 };
35
36 struct vfio_device {
37 struct device *dev;
38 const struct vfio_device_ops *ops;
39 /*
40 * mig_ops/log_ops is a static property of the vfio_device which must
41 * be set prior to registering the vfio_device.
42 */
43 const struct vfio_migration_ops *mig_ops;
44 const struct vfio_log_ops *log_ops;
45 struct vfio_group *group;
46 struct vfio_device_set *dev_set;
47 struct list_head dev_set_list;
48 unsigned int migration_flags;
49 struct kvm *kvm;
50
51 /* Members below here are private, not for driver use */
52 unsigned int index;
53 struct device device; /* device.kref covers object life circle */
54 refcount_t refcount; /* user count on registered device*/
55 unsigned int open_count;
56 struct completion comp;
57 struct list_head group_next;
58 struct list_head iommu_entry;
59 struct iommufd_access *iommufd_access;
60 void (*put_kvm)(struct kvm *kvm);
61 #if IS_ENABLED(CONFIG_IOMMUFD)
62 struct iommufd_device *iommufd_device;
63 struct iommufd_ctx *iommufd_ictx;
64 bool iommufd_attached;
65 #endif
66 };
67
68 /**
69 * struct vfio_device_ops - VFIO bus driver device callbacks
70 *
71 * @init: initialize private fields in device structure
72 * @release: Reclaim private fields in device structure
73 * @bind_iommufd: Called when binding the device to an iommufd
74 * @unbind_iommufd: Opposite of bind_iommufd
75 * @attach_ioas: Called when attaching device to an IOAS/HWPT managed by the
76 * bound iommufd. Undo in unbind_iommufd.
77 * @open_device: Called when the first file descriptor is opened for this device
78 * @close_device: Opposite of open_device
79 * @read: Perform read(2) on device file descriptor
80 * @write: Perform write(2) on device file descriptor
81 * @ioctl: Perform ioctl(2) on device file descriptor, supporting VFIO_DEVICE_*
82 * operations documented below
83 * @mmap: Perform mmap(2) on a region of the device file descriptor
84 * @request: Request for the bus driver to release the device
85 * @match: Optional device name match callback (return: 0 for no-match, >0 for
86 * match, -errno for abort (ex. match with insufficient or incorrect
87 * additional args)
88 * @dma_unmap: Called when userspace unmaps IOVA from the container
89 * this device is attached to.
90 * @device_feature: Optional, fill in the VFIO_DEVICE_FEATURE ioctl
91 */
92 struct vfio_device_ops {
93 char *name;
94 int (*init)(struct vfio_device *vdev);
95 void (*release)(struct vfio_device *vdev);
96 int (*bind_iommufd)(struct vfio_device *vdev,
97 struct iommufd_ctx *ictx, u32 *out_device_id);
98 void (*unbind_iommufd)(struct vfio_device *vdev);
99 int (*attach_ioas)(struct vfio_device *vdev, u32 *pt_id);
100 int (*open_device)(struct vfio_device *vdev);
101 void (*close_device)(struct vfio_device *vdev);
102 ssize_t (*read)(struct vfio_device *vdev, char __user *buf,
103 size_t count, loff_t *ppos);
104 ssize_t (*write)(struct vfio_device *vdev, const char __user *buf,
105 size_t count, loff_t *size);
106 long (*ioctl)(struct vfio_device *vdev, unsigned int cmd,
107 unsigned long arg);
108 int (*mmap)(struct vfio_device *vdev, struct vm_area_struct *vma);
109 void (*request)(struct vfio_device *vdev, unsigned int count);
110 int (*match)(struct vfio_device *vdev, char *buf);
111 void (*dma_unmap)(struct vfio_device *vdev, u64 iova, u64 length);
112 int (*device_feature)(struct vfio_device *device, u32 flags,
113 void __user *arg, size_t argsz);
114 };
115
116 #if IS_ENABLED(CONFIG_IOMMUFD)
117 int vfio_iommufd_physical_bind(struct vfio_device *vdev,
118 struct iommufd_ctx *ictx, u32 *out_device_id);
119 void vfio_iommufd_physical_unbind(struct vfio_device *vdev);
120 int vfio_iommufd_physical_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
121 int vfio_iommufd_emulated_bind(struct vfio_device *vdev,
122 struct iommufd_ctx *ictx, u32 *out_device_id);
123 void vfio_iommufd_emulated_unbind(struct vfio_device *vdev);
124 int vfio_iommufd_emulated_attach_ioas(struct vfio_device *vdev, u32 *pt_id);
125 #else
126 #define vfio_iommufd_physical_bind \
127 ((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx, \
128 u32 *out_device_id)) NULL)
129 #define vfio_iommufd_physical_unbind \
130 ((void (*)(struct vfio_device *vdev)) NULL)
131 #define vfio_iommufd_physical_attach_ioas \
132 ((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
133 #define vfio_iommufd_emulated_bind \
134 ((int (*)(struct vfio_device *vdev, struct iommufd_ctx *ictx, \
135 u32 *out_device_id)) NULL)
136 #define vfio_iommufd_emulated_unbind \
137 ((void (*)(struct vfio_device *vdev)) NULL)
138 #define vfio_iommufd_emulated_attach_ioas \
139 ((int (*)(struct vfio_device *vdev, u32 *pt_id)) NULL)
140 #endif
141
142 /**
143 * @migration_set_state: Optional callback to change the migration state for
144 * devices that support migration. It's mandatory for
145 * VFIO_DEVICE_FEATURE_MIGRATION migration support.
146 * The returned FD is used for data transfer according to the FSM
147 * definition. The driver is responsible to ensure that FD reaches end
148 * of stream or error whenever the migration FSM leaves a data transfer
149 * state or before close_device() returns.
150 * @migration_get_state: Optional callback to get the migration state for
151 * devices that support migration. It's mandatory for
152 * VFIO_DEVICE_FEATURE_MIGRATION migration support.
153 * @migration_get_data_size: Optional callback to get the estimated data
154 * length that will be required to complete stop copy. It's mandatory for
155 * VFIO_DEVICE_FEATURE_MIGRATION migration support.
156 */
157 struct vfio_migration_ops {
158 struct file *(*migration_set_state)(
159 struct vfio_device *device,
160 enum vfio_device_mig_state new_state);
161 int (*migration_get_state)(struct vfio_device *device,
162 enum vfio_device_mig_state *curr_state);
163 int (*migration_get_data_size)(struct vfio_device *device,
164 unsigned long *stop_copy_length);
165 };
166
167 /**
168 * @log_start: Optional callback to ask the device start DMA logging.
169 * @log_stop: Optional callback to ask the device stop DMA logging.
170 * @log_read_and_clear: Optional callback to ask the device read
171 * and clear the dirty DMAs in some given range.
172 *
173 * The vfio core implementation of the DEVICE_FEATURE_DMA_LOGGING_ set
174 * of features does not track logging state relative to the device,
175 * therefore the device implementation of vfio_log_ops must handle
176 * arbitrary user requests. This includes rejecting subsequent calls
177 * to log_start without an intervening log_stop, as well as graceful
178 * handling of log_stop and log_read_and_clear from invalid states.
179 */
180 struct vfio_log_ops {
181 int (*log_start)(struct vfio_device *device,
182 struct rb_root_cached *ranges, u32 nnodes, u64 *page_size);
183 int (*log_stop)(struct vfio_device *device);
184 int (*log_read_and_clear)(struct vfio_device *device,
185 unsigned long iova, unsigned long length,
186 struct iova_bitmap *dirty);
187 };
188
189 /**
190 * vfio_check_feature - Validate user input for the VFIO_DEVICE_FEATURE ioctl
191 * @flags: Arg from the device_feature op
192 * @argsz: Arg from the device_feature op
193 * @supported_ops: Combination of VFIO_DEVICE_FEATURE_GET and SET the driver
194 * supports
195 * @minsz: Minimum data size the driver accepts
196 *
197 * For use in a driver's device_feature op. Checks that the inputs to the
198 * VFIO_DEVICE_FEATURE ioctl are correct for the driver's feature. Returns 1 if
199 * the driver should execute the get or set, otherwise the relevant
200 * value should be returned.
201 */
vfio_check_feature(u32 flags,size_t argsz,u32 supported_ops,size_t minsz)202 static inline int vfio_check_feature(u32 flags, size_t argsz, u32 supported_ops,
203 size_t minsz)
204 {
205 if ((flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)) &
206 ~supported_ops)
207 return -EINVAL;
208 if (flags & VFIO_DEVICE_FEATURE_PROBE)
209 return 0;
210 /* Without PROBE one of GET or SET must be requested */
211 if (!(flags & (VFIO_DEVICE_FEATURE_GET | VFIO_DEVICE_FEATURE_SET)))
212 return -EINVAL;
213 if (argsz < minsz)
214 return -EINVAL;
215 return 1;
216 }
217
218 struct vfio_device *_vfio_alloc_device(size_t size, struct device *dev,
219 const struct vfio_device_ops *ops);
220 #define vfio_alloc_device(dev_struct, member, dev, ops) \
221 container_of(_vfio_alloc_device(sizeof(struct dev_struct) + \
222 BUILD_BUG_ON_ZERO(offsetof( \
223 struct dev_struct, member)), \
224 dev, ops), \
225 struct dev_struct, member)
226
vfio_put_device(struct vfio_device * device)227 static inline void vfio_put_device(struct vfio_device *device)
228 {
229 put_device(&device->device);
230 }
231
232 int vfio_register_group_dev(struct vfio_device *device);
233 int vfio_register_emulated_iommu_dev(struct vfio_device *device);
234 void vfio_unregister_group_dev(struct vfio_device *device);
235
236 int vfio_assign_device_set(struct vfio_device *device, void *set_id);
237 unsigned int vfio_device_set_open_count(struct vfio_device_set *dev_set);
238
239 int vfio_mig_get_next_state(struct vfio_device *device,
240 enum vfio_device_mig_state cur_fsm,
241 enum vfio_device_mig_state new_fsm,
242 enum vfio_device_mig_state *next_fsm);
243
244 /*
245 * External user API
246 */
247 struct iommu_group *vfio_file_iommu_group(struct file *file);
248 bool vfio_file_is_group(struct file *file);
249 bool vfio_file_enforced_coherent(struct file *file);
250 void vfio_file_set_kvm(struct file *file, struct kvm *kvm);
251 bool vfio_file_has_dev(struct file *file, struct vfio_device *device);
252
253 #define VFIO_PIN_PAGES_MAX_ENTRIES (PAGE_SIZE/sizeof(unsigned long))
254
255 int vfio_pin_pages(struct vfio_device *device, dma_addr_t iova,
256 int npage, int prot, struct page **pages);
257 void vfio_unpin_pages(struct vfio_device *device, dma_addr_t iova, int npage);
258 int vfio_dma_rw(struct vfio_device *device, dma_addr_t iova,
259 void *data, size_t len, bool write);
260
261 /*
262 * Sub-module helpers
263 */
264 struct vfio_info_cap {
265 struct vfio_info_cap_header *buf;
266 size_t size;
267 };
268 struct vfio_info_cap_header *vfio_info_cap_add(struct vfio_info_cap *caps,
269 size_t size, u16 id,
270 u16 version);
271 void vfio_info_cap_shift(struct vfio_info_cap *caps, size_t offset);
272
273 int vfio_info_add_capability(struct vfio_info_cap *caps,
274 struct vfio_info_cap_header *cap, size_t size);
275
276 int vfio_set_irqs_validate_and_prepare(struct vfio_irq_set *hdr,
277 int num_irqs, int max_irq_type,
278 size_t *data_size);
279
280 /*
281 * IRQfd - generic
282 */
283 struct virqfd {
284 void *opaque;
285 struct eventfd_ctx *eventfd;
286 int (*handler)(void *, void *);
287 void (*thread)(void *, void *);
288 void *data;
289 struct work_struct inject;
290 wait_queue_entry_t wait;
291 poll_table pt;
292 struct work_struct shutdown;
293 struct virqfd **pvirqfd;
294 };
295
296 int vfio_virqfd_enable(void *opaque, int (*handler)(void *, void *),
297 void (*thread)(void *, void *), void *data,
298 struct virqfd **pvirqfd, int fd);
299 void vfio_virqfd_disable(struct virqfd **pvirqfd);
300
301 #endif /* VFIO_H */
302